FRIDAY, May 3 (HealthDay News) -- Centenarians are more likely to be content with their lives than aging baby boomers are, and these oldest Americans tend to put more stock in healthy eating habits and exercise as keys to happiness, a new survey finds.

Half of Americans aged 100 and older wouldn't change a thing about the way they lived their lives, while only 29 percent of Baby Boomers (aged 60 to 65) would leave their pasts untouched and 26 percent wished they had made more money. Baby boomers were also more than twice as likely as centenarians to wish they had taken more risks in their lives, 12 percent vs. 5 percent.

The average American today lives to be about 80, according to the U.S. Centers for Disease Control and Prevention. When asked what could have made their extra 20 or more years even better, 33 percent of the centenarians said nothing, while 33 percent wished for more time with their spouse or loved ones, 13 percent wished for better health and only 6 percent wished they had more money, according to the UnitedHealthcare's eighth annual 100@100 survey.

Nearly all centenarians (98 percent) said that keeping their mind active is a secret to healthy aging, and 100 percent of baby boomers agreed. Staying mobile and exercising is also important, according to 96 percent of centenarians and 98 percent of the baby boomers.

Both age groups also agree that physical health is more difficult to maintain as they age, compared with mental health, emotional/spiritual health, social connections and independence.

Many centenarians try to remain active. More than half said they walk or hike weekly, more than one-third said they do strength training exercises at least once a week, and nearly 20 percent do a cardiovascular workout indoors one or more times a week.

Centenarians and baby boomers do differ on other healthy habits. Centenarians are more likely than the boomers to eat nutritiously balanced meals regularly (86 percent vs. 77 percent), to get more than eight hours of sleep per night (66 percent vs. 54 percent), and to attend a social event every day (37 percent vs. 28 percent).

Only 31 percent of centenarians said that maintaining one's sex life is important for healthy aging, compared with 80 percent of the boomers. Centenarians were also less likely than the boomers to believe that it's very important to continue to look forward to each day (72 percent vs. 88 percent) and to maintain a sense of purpose (57 percent vs. 79 percent).

While 29 percent of centenarians said they expected to live to 100, only 21 percent of the boomers said they expect to reach the same milestone. But a good number of them might make that goal. The centenarian population in the United States is expected to grow to more than 600,000 by 2050, according to the U.S. Census Bureau.

"The centenarians in this year's 100@100 survey show that maintaining a positive outlook isn't all about focusing on what the future holds," Dr. Rhonda Randall, chief medical officer of UnitedHealthcare Medicare & Retirement, said in a company news release.

"Reflecting fondly and confidently on the choices they've made throughout their lives helps the longest-living Americans maintain a sense of satisfaction and well-being that's vital to healthy aging," she said.

Young adulthood was the most fondly remembered time in centenarians' lives (45 percent), despite challenges such as balancing the demands of work and family. The second most fondly remembered time in centenarians' lives was approaching their 100th birthday (12 percent).

There were notable differences between the two groups in their view of marriage or life partnership. Thirty-one percent of centenarians and 19 percent of the boomers said that sharing the same political views as your partner is very important, 40 percent of centenarians and 22 percent of boomers said having the same hobbies as your partner is very important, and 56 percent of centenarians and 46 percent of boomers said sharing the same religious faith as your partner is very important.

Only 49 percent of boomers said that it's very important to maintain the traditional roles of husband and wife, compared with 67 percent of centenarians.

Both groups said that friends and family have the biggest impact on their lives and provide them with the most support. Staying close to friends and family is a secret to healthy aging for 97 percent of centenarians and 99 percent of boomers, and more than one-third of centenarians said they've maintained a friendship for more than 75 years.